噪声数值 meaning in English

noise figure

In the thesis the low drag - low noise optimization of the vehicle main form design is realized , main accomplishments are as follows . researched the knowledge of drag and flow noise , the parameters of the boundary layer are calculated by the hess - smith method and boundary layer momentum integral method . the calculation of the length of transition zone and change in boundary layer displacement thickness between laminar and turbulent states in the transition is improved , then the drag coefficient and self - noise from the transition zone are calculated as the objective functions of the optimization
主要研究内容和成果如下：对航行器绕流流场进行分析，深入研究了阻力和流噪声产生机理，建立了阻力系数和自噪声的评估数值计算模型；采用物面分布源汇法和边界层动量积分法对绕流流场的流体动力参数进行计算，改进了转捩区长度和边界层位移厚度的计算，应用于航行器头部驻点自噪声的计算；最后设计了阻力系数和自噪声数值计算程序模块。